Design of a wide field diffractive landscape lens

TLDR

The study derives third‑order aberrations of a diffractive element with paraxial zone spacings as a function of aperture‑stop position and discusses spherical‑aberration correction via an aspheric plate at the stop, including non‑monochromatic imaging performance. By positioning the stop in the front focal plane, the design eliminates coma, astigmatism, and the Petzval sum, achieves MTF performance comparable to other lenses, provides appropriate distortion for Fourier‑transform imaging, and yields a quantified space‑bandwidth product.

Abstract

The third-order aberrations of a diffractive optical element with paraxial zone spacings are derived as a function of aperture stop position. It is shown that by placing the stop in the front focal plane, coma and astigmatism are identically zero, assuming an infinitely distant object. In addition, since the element is diffractive, the Petzval sum is also zero. Modulation transfer function comparisons with other lenses are given. The correction of spherical aberration using an aspheric plate located in the aperture stop and nonmonochromatic imaging performance are discussed. The distortion of the resulting system is shown to be the proper amount for use as a Fourier transform lens. An estimate for the space-bandwidth product of this Fourier transform system is given.